Actually at 10hPa I wouldn’t be so certain that it has finished developing, and technically it’s now outside the 30%-70% distribution curve, even if only just:

http://acdb-ext.gsfc.nasa.gov/Data_s...0n_10_2010.pdf

So this particular stratospheric warming currently may not be particularly profound, I’m not sure if Will ever did quantify the intensity he expected it to reach? And who knows this modest positive anomaly, possibly combined with some other dynamic event, *could* be responsible for a “bitter spell” of weather after the 18th January. Again Will never really quantified the intensity of the cold spell, simply describing it as “bitter”. If I recall correctly, in her past forecasts Penny Tranter has referred to temperatures of +4C with a modest breeze as being “bitter”, admittedly that used to make me laugh!
As I have long forgotten any dynamical meteorology I may or may not have learnt at Reading in the 80s I certainly wouldn’t be so bold to rule in or out a link between the current modest positive stratospheric warming and any “bitter” weather that may occur after the 18th Jan.

Alan wrote:
Actually at 10hPa I wouldn’t be so certain that it has finished
developing, and technically it’s now outside the 30%-70% distribution
curve, even if only just:

http://acdb-ext.gsfc.nasa.gov/Data_s...0n_10_2010.pdf

So this particular stratospheric warming currently may not be
particularly profound, I’m not sure if Will ever did quantify the
intensity he expected it to reach? And who knows this modest
positive anomaly, possibly combined with some other dynamic event,
*could* be responsible for a “bitter spell” of weather after the 18th
January. Again Will never really quantified the intensity of the
cold spell, simply describing it as “bitter”. If I recall correctly,
in her past forecasts Penny Tranter has referred to temperatures of
+4C with a modest breeze as being “bitter”, admittedly that used to
make me laugh!
As I have long forgotten any dynamical meteorology I may or may not
have learnt at Reading in the 80s I certainly wouldn’t be so bold to
rule in or out a link between the current modest positive
stratospheric warming and any “bitter” weather that may occur after
the 18th Jan.

I would certainly think that 'bitter' meant something at least approaching
the conditions we had in December.
On 20th December I recorded a *max* of -6.3C so it has quite
something to live up to
--
Col

Bolton, Lancashire
160m asl

On Jan 15, 10:44*am, Alan wrote:
Actually at 10hPa I wouldn’t be so certain that it has finished developing, and technically it’s now outside the 30%-70% distribution curve, even if only just:

http://acdb-ext.gsfc.nasa.gov/Data_s.../annual/t60_90...

So this particular stratospheric warming currently may not be particularly profound, I’m not sure if Will ever did quantify the intensity he expected it to reach? *And who knows this modest positive anomaly, possibly combined with some other dynamic event, *could* be responsible for a “bitter spell” of weather after the 18th January. *Again Will never really quantified the intensity of the cold spell, simply describing it as “bitter”. If I recall correctly, in her past forecasts Penny Tranter has referred to temperatures of +4C with a modest breeze as being “bitter”, admittedly that used to make me laugh!
As I have long forgotten any dynamical meteorology I may or may not have learnt at Reading in the 80s I certainly wouldn’t be so bold to rule in or out a link between the current modest positive stratospheric warming and any “bitter” weather that may occur after the 18th Jan.

Yup. Agreed. - who knows? However we do know that what was foretold
was a retun to the bitter weather we had before the "sucker's gap".
Unlikely, but let's wait until outcome for that one.

"Col" wrote in message
...
snip

I would certainly think that 'bitter' meant something at least approaching
the conditions we had in December.
On 20th December I recorded a *max* of -6.3C so it has quite
something to live up to

Col, bitter is usually when day maxes are close to zero, often with a
breeze. December was "extremely bitter" or even 'historic' :-)

Will
--

In article ,
Col writes:
I would certainly think that 'bitter' meant something at least approaching
the conditions we had in December.
On 20th December I recorded a *max* of -6.3C so it has quite
something to live up to

My own personal definition of "bitter" requires maxima very close to, or
below, freezing. That would usually require 850mb temperatures closer to
-10C than to -5C (though obviously that need not apply if there's an
inversion). Arguably wind speed should be factored into my definition
too.
--
John Hall
"I look upon it, that he who does not mind his belly,
will hardly mind anything else."
Dr Samuel Johnson (1709-84)

On Saturday 15 Jan 2011 19:20, John Hall scribbled:

In article ,
Col writes:
I would certainly think that 'bitter' meant something at least approaching
the conditions we had in December.
On 20th December I recorded a *max* of -6.3C so it has quite
something to live up to

My own personal definition of "bitter" requires maxima very close to, or
below, freezing. That would usually require 850mb temperatures closer to
-10C than to -5C (though obviously that need not apply if there's an
inversion). Arguably wind speed should be factored into my definition
too.

The first time I heard it used by forecasters on TV was during the 1962-3
winter. In those days, they used to use official descriptions such as
"rather cold" or "very cold". On one broadcast, the forecaster admitted he'd
run out of adequate descriptions, having already used "extremely cold", and
so introduced "bitterly cold". As I recall it, this occurred when
temperatures were in the region of -5C and in association with gale force
winds.

--
Graham Davis, Bracknell
It was raining cats and dogs and I fell in a poodle. [Chic
Murray(1919-1985)]